Known solutions of converting vibrations of strings, in musical instruments, into electric signals involve typically a use of coils.
A ferromagnetic string passing through the magnetic field induces electric current in the coil wound on a pole of a permanent magnet. The electric current induced in this way has the same frequency as the frequency of the vibrating string. Obtained in this way signal is amplified and played back by a speaker at much higher power.
This solution is very prone to electromagnetic interference due to the high sensitivity of such solutions needed for high efficiency in converting musical instrument string vibrations into electric signals.
Moreover, the need of connecting such sound sensors to potentiometers for volume and tone control as well as to the outlet socket pose additional problems for interference-free sound signal transmission especially at the stage where the level of signals is very small and prone to unwanted signal interference.
One additional limitation is a necessity of having a ferromagnetic string in a musical instrument, which is needed to induce electric current in the pick-up coils. This way of transforming the vibration of strings into electric signal is not suitable for instruments having nylon or gut strings which do not induce electric current in coil based pick-up systems.
Another way of transforming vibrations of physical elements into electric signal involves the use of microphones or piezo-electric devices. Both solutions transform vibrations of air or mechanical elements onto electric signals, which are subject of further processing or amplification.
With piezo-electric sound pick-ups or microphones there is no necessity of having ferromagnetic strings, but instrument producers face problems with unwanted feedback, crosstalk or noise interference at the early stage of sound signal processing and amplification.
Other, less popular and practically hardly implemented, known solutions of converting the vibrations of strings into electric signals apply the use of optic sensors as described in U.S. Pat. No. 8,546,677, where an emitted light stream or laser beam or any other form of electromagnetic waves of different length is interrupted by the vibrating string and the optical sensor receiving the interrupted in this way light/infrared stream or reflections are the source of the string frequency response.
In a way, this solution is similar to the coil based pick-up with the difference that instead of the magnetic field interrupted by the vibrating ferromagnetic string it is the emitted light that gets interrupted by the vibrating string and received by a suitably placed light sensor.
Although the employment of light or any other form of electromagnetic waves of various length decreases the unwanted noise interference signals being a major problem with magnetic coil, microphone, or piezo based solutions, it cannot produce any form of information about the way of sound generation related to the physical application of force inducing the string vibration.
This information, called in music “sound articulation”, can only be heard when the sensed and amplified sound is reproduced by a speaker. In electronic music sound modules, information about sound articulation is described by the duration and dynamics of sound. This may be regarded as a limitation in musical expression especially when musicians use electronic stringed instruments and MIDI based sound modules.
An advantage of keyboard instruments over stringed instruments in MIDI electronic sound systems have led to the search of other means of collecting information about the produced by a stringed instrument sound.
In view of the above, the aim of the development of the present invention is an improved or at least alternative system and method for stringed instruments' pickup.